LOFAR observes across borders

An international group of astronomers have succeeded in the first joint observations between the LOFAR stations in Exloo (The Netherlands) and Effelsberg (Germany). This constitutes the "first light" of the LOFAR telescope as an international array. The bright quasar 3C 196, located almost ten billion light years away from Earth, was detected successfully on 2009 August 20 providing first "interferometric fringes", equivalent to the "first light" for an ordinary telescope.

Olaf Wucknitz, astronomer at the Argelander-Institut für Astronomy of the University of Bonn, found conclusive proof of the detection on 2009 August 31, after initial analysis of the data by astronomers from ASTRON (Dwingeloo, NL), the University of Manchester (UK), and the Max-Planck-Institut für Radioastronomie (MPIfR; Bonn, DE). Wucknitz is enthusiastic: "Our results demonstrate the ability of LOFAR to work with stations widely separated across different countries."

Prof. Michael Garrett, General Director at ASTRON commented: "Our colleagues in Bonn have shown that these joint observations, where different LOFAR stations with distances of hundreds of kilometers are used, are not only a dream anymore but a practical reality - a completely new window on the universe beckons towards us - we may not falter - the potential for scientific discovery is unprecedented." From the MPIfR, Anton Zensus added: "The LOFAR telescope station in Effelsberg and other international stations will make important contributions to the scientific success of LOFAR, and serve as a major step towards realizing a high-resolution pathfinder for future telescopes such as the Square Kilometer Array."

André Gunst, leader of the LOFAR Technical Team at ASTRON, says: "I'm very proud that we have now proven all of the different LOFAR elements fit together, even across borders."

Michael Kramer from the MPIfR is anxious to get his hands on the new telescope: "These first fringes between the Effelsberg and Dutch stations represent not only the first step towards a fantastic new telescope, but are also the result of a very fruitful European collaboration between partners from various research institutes and universities. The MPIfR is proud to be a partner and we look forward to the first scientific results!"

For James Anderson, station manager of the Effelsberg LOFAR station, this day has been a long time coming. "The first fringe detection by Effelsberg and Exloo is a major milestone in the European LOFAR project".

Figure: Sketch of the LOFAR stations used for the first international fringe detection. Top right, the station RS302 near Exloo, in the Netherlands. Bottom left, the station DE1 in Effelsberg.
Image: E. Ros (Univ. Valencia/MPIfR); Inlets: ASTRON & MPIfR.